Active Subwoofer filter circuit based on the frequency between 18 Hz 200 Hz ne5532 op ampar setting. Subwoofer Filter circuit power supply 15v dc rectifier +-7815, gathered on a single pcb pcb li regulator 7915 times the design of... Electronics Projects, 18Hz-200Hz Active Subwoofer filter circuit NE5532 "audio control circuits, " Date 2019/08/03